1. Field of the Invention
This invention relates to conductive charge removal from hovercraft and more particularly to conductive charge removal via a liquid stream that completes a conductive path between the hovercraft and earth ground.
2. Prior Art
The risk of electrocution from first contact with a hovercraft by persons at earth ground is well known, and actual potentials and charging rates have been measured and are detailed in (U.S.) Naval Research Laboratories Memorandum Report Number 5676, Electrostatic Charging of the CH-53E Helicopter, Pechacek et al.
Eisenhauer, U.S. Pat. No. 4,059,846, describes a sea-rescue arrangement in which a raft is lowered to and raised from the sea surface by a helicopter, and in which the potential difference between the raft and the sea is eliminated by a weighted grounding wire that hangs below, and makes first contact with, the water. While Eisenhauer's arrangement is quite satisfactory for its intended purpose of stand-by rescue at power boat races, it is an impractical arrangement for rescue in combat situations where rafts are not generally used and the weight can injure victims and/or the rescuers that enter the water to assist them, and the wire can become entangled in helicopter rotor blades.
Corbin, U.S. Pat. No. 3,893,005, describes a grounded pole that is used to drain charge from and to attach a load to a helicopter. While Corbin's arrangement may be effective in the hands of a skilled user, in combat situations where the pole is unavailable or the ground crew has never used one, the load can be expected to be hooked up to the helicopter by someone who also becomes part of the electrical path to ground.
Crossley, U.S. Pat. No. 1,757,111, describes an arrangement that provides an electrically conductive path between a flightcraft (a balloon) and ground, but is otherwise of little relevance here.